"Why I quit" by Linux kernel developer Con Kolivas
apcmag.com
apcmag.com
Reading the article it seems like the requirements of desktops and servers are sufficiently different to deserve separate kernels. It certainly wasn't worth his time to keep working with the kernel developers if they refused to fairly examine his contributions.
Although I think splitting the kernel into separate products for different applications is a problem as well. What it really comes down to at that point is where are you planning on taking your product?
Are you satisfied with a big market with large customers, or do you really want a huge market with nearly unlimited small customers. f Linux really wants to be on the desktop, they will have to moderate some of their features that are enterprise only to make the desktop experience better.
The GPL pretty much ensure a server centric development model on Linux, though. Most open source developers and supporters aren't quite so 'open' with their own companies' source code, thus preferring to 'distribute' their apps as web apps, requiring no source disclosure.